Speaker Question

[ez_willis]

I have a dead one. It's a 1-15" Ampeg cabinet and I am getting nothing out of it. My question is, should it be a closed circuit from terminal to terminal? I did a continuity test on it and it's open. Not sure I have a firm understanding of how speakers work, though. Or electronic circuits. lol.

[Greg_L]

It should read whatever ohms the speaker is rated for...give or take a few ohms.

[ez_willis]

hmmm.

[Bubba]

Connect a 9v battery between the terminals. If the cone moves then the speaker is probably ok.

[ez_willis]

Connect a 9v battery between the terminals. If the cone moves then the speaker is probably ok.

What would cause it to not be ok? I've blown a speaker before but I can't recall one just being totally dead.

[ez_willis]

It should read whatever ohms the speaker is rated for...give or take a few ohms.

But on a continuity test should it be a closed circuit? I have the cabinet with me at work and asked an electrician to just do a continuity test. Maybe I should have had him test the ohms?

[Bubba]

Connect a 9v battery between the terminals. If the cone moves then the speaker is probably ok.

What would cause it to not be ok? I've blown a speaker before but I can't recall one just being totally dead.

When you say you blew a speaker, did you break the cone or burn out the coil? If the coil is broken then it won't pass any current. Basically, a speaker is a coil of wire stuck to the bottom of a paper cone. The coil is immersed in a strong magnetic field. When you pass a current through the coil it produces movement which is translated by the cone into sound waves. If the wire is broken then there is no current flowing and no movement. Sorry if you already know all this.

[ez_willis]

When you say you blew a speaker, did you break the cone or burn out the coil? If the coil is broken then it won't pass any current. Basically, a speaker is a coil of wire stuck to the bottom of a paper cone. The coil is immersed in a strong magnetic field. When you pass a current through the coil it produces movement which is translated by the cone into sound waves. If the wire is broken then there is no current flowing and no movement. Sorry if you already know all this.

This is what I was looking for. This speaker isn't doing anything. No sound at all. I didn't pull the grill at rehearsal last night so I didn't actually check movement but there was no sound.

And it sounds like on a functioning speaker if I do a continuity test from one terminal to the other it should be a closed circuit right? This is my question.

[Greg_L]

This is what I was looking for. This speaker isn't doing anything. No sound at all. I didn't pull the grill at rehearsal last night so I didn't actually check movement but there was no sound.

And it sounds like on a functioning speaker if I do a continuity test from one terminal to the other it should be a closed circuit right? This is my question.

It should have continuity, but at a specific resistance. What Bubba said is also true - a coil can pass current but not move the paper. With the battery test you can easily see the cone jump back and forth if all is well. If you use a "beep" continuity tester, that will show you continuity, but only tell a tiny piece of the whole picture.

[ez_willis]

With the battery test you can easily see the cone jump back and forth if all is well. If you use a "beep" continuity tester, that will show you continuity, but only tell a tiny piece of the whole picture.

I think I know what you mean. I'm probably not explaining it correctly. No matter what, if the circuit isn't closed between the two terminals the speaker is dead. Correct?

[Greg_L]

I think I know what you mean. I'm probably not explaining it correctly. No matter what, if the circuit isn't closed between the two terminals the speaker is dead. Correct?

Yes, I think that would be a problem no matter what shape the cone is in.

[ez_willis]

Yes, I think that would be a problem no matter what shape the cone is in.

Perfect. Thanks.